This document provides an overview of significant events and developments in the Christian church between AD 100-300. It discusses the rise of false teachings like Gnosticism and Marcionism and the response of early Christian apologists in defending orthodox doctrine. It also describes changes in church structure as leadership roles became more clearly defined and congregations began meeting in dedicated buildings. Important figures that defended the faith through their writings and martyrdom are highlighted, including Justin Martyr, Polycarp, Irenaeus, Tertullian, Perpetua, and Origen. The document also discusses Roman persecution of Christians in the mid-3rd century over refusal to participate in imperial birthday celebrations that involved pagan sacrifices.